3 broken spokes is more than a fluke.

4 years shouldn't cause undue stress or corrosion unless you're on it all the time or leaving it out in terrible conditions.

The technique of lifting the front wheel up and slamming the back up and over the curb is pretty awful for a road bike. If you're doing that, you've got to find a better way up and over things. Either a proper bunny hop or just finding a different spot to mount the curb.

I do work on my own wheels. If I was in your situation, I'd replace the rim and spokes/nips. It's honestly not that hard, loads of videos. It'll cost you $200, about $120 for the rim and $80 for spokes. You'll end up with a better rim than $200 could but you. I often end up buying a new hub, because when I consider my time and long term, it's a very easy talk myself into an upgrade.

I'd also see what the widest tire I could use on your frame is, and use it.